This invention relates to an air filter element system for providing new and unique filtering design including at least one three dimensional piece of filtering material folded over on itself to provide a biasing means for the filtering system. The filter system is held together in a new and improved metal or fabric frame.
In the past, various filters having layers of filter elements have been proposed but not in a practical system for everyday use in order to substantially reduce maintenance costs and the cost of throwaway filters. One such filter is shown in the U.S. Pat. No. 2,804,937. Further, this invention avoids the use of materials that deteriorate in adverse environments.